Field of the Invention
The invention relates to a structural member for an exhaust-gas connection of a turbomachine and a turbomachine bearing disposed in the exhaust-gas connection. The invention also relates to a set of at least two structural members.
The invention relates in particular to an exhaust-gas connection for connecting a steam turbine to a condenser. The steam turbine expands the steam which serves as a fluidic medium, until the steam condenses. In particular, reference is made to an exhaust-gas connection which directs the steam flowing from the steam turbine essentially rectilinearly to the condenser. A configuration that is made in such a way and has a steam turbine, an exhaust-gas connection and a condenser, is constructed in particular for a steam turbine having a mechanical output of up to about 300 MW, as used in a combined-cycle power station. A combined-cycle power station is a power station in which mechanical output is produced both by a gas turbine and by a steam turbine, with exhaust gases from the gas turbine being used to prepare steam for the steam turbine. Within the scope of one embodiment which is of special interest in the market at present, the exhaust gas from the gas turbine is the sole heat source for preparing the steam.
According to conventional practice, an exhaust-gas connection of the type mentioned at the beginning is preferably made as a welded construction, i.e. it is welded together from appropriately formed steel plates. A frame for a bearing which is possibly required in the interior of the exhaust-gas connection is joined to the actual exhaust-gas connection through welded-in supports. Requisite feed lines and discharge lines for operating the bearing, in particular feed lines for lubricating oil, pressure oil, sealing steam and air as well as discharge lines for oil, oil mist and low-tension steam together with any requisite cables for electric and electronic components for monitoring and possibly controlling the bearing, must be run in separate pipe ducts from outside the exhaust-gas connection and through the exhaust-gas connection to the bearing. That necessitates complicated structures, since complete tightness is required between the interior space of the exhaust-gas connection, through which the condensing steam has to flow, and the bearing, in order to prevent oil or air from passing from the bearing into the condensing steam. That is because oil or air would considerably impair the thermodynamic process taking place in the steam turbine. For those reasons, the complicated structures resulting heretofore have a further disadvantage irrespective of whether the configurations of supporting arms, supports and pipe conduits are fitted like a lattice or in each case in a radial direction into the exhaust-gas connection. Those fitted components always impair the flow of the steam to a quite considerable extent and lead to back pressure at the outlet of the steam turbine being increased. The back pressure, inter alia, determines the output delivered by the steam turbine. The meaning thereof is that its output and its efficiency are adversely affected.
Swiss Patent CH 570 549 A5, corresponding to U.S. Pat. No. 4,076,452; Swiss Patent CH 685 448 A5; and U.S. Pat. No. 2,414,814, disclose exhaust-gas connections in welded and/or bolted form or in a form assembled in another way from individual parts.
Other disadvantages of the previous embodiments for exhaust-gas connections are the result of the high cost that is necessary for producing such exhaust-gas connections.